From the satellite navigator in your car to the labels of your publications on social networks, many of us use global positioning systems, better known by their initials, GPS. For that we can thank Gladys West. She was one of the people whose work was instrumental in the development of the mathematical operations behind the GPS. However, until now, her story had not been told. A retired mathematician, now 87, she lives in northeastern Virginia. The US Navy, her former employer, believes she has played a pivotal role in the development of GPS technology. When West began her career at the Naval Surface Warfare Center, a Navy research center in Virginia, United States, in 1956, there was only one other black woman and two black men in that place.

West was born in 1930 in Dinwiddie County, Virginia, a "very rural" site, she says. Many of the families rented land and then gave the owners a share of what they harvested. Her family had a small farm, and she had to work in the fields with them. "It was a bit the opposite of what I had in mind," she says. West had other ambitions: she did not want to stay there picking tobacco, corn or cotton as her neighbors. Nor did she want to work in a nearby factory, crushing the tobacco leaves to make cigarettes or prepare pipe tobacco.

"At first I thought I had to go to the city," she says, remembering that she thought that would help her quit that job. "But later, when I was accessing more education, I got higher grades and I learned that education was what would help me get out of there. At their school, the students who obtained the best grades were offered a scholarship to the local university. Her family "did not have much money", and West knew that this was her great opportunity. She worked hard, graduated with the best grades in her class, and secured the scholarship. "When it was time to go to college, I did not know what to study," she explains. "They tried to tell me that, because I was good at all subjects, I had to graduate in science or mathematics or something more difficult, that not many people studied."

West decided on mathematics, a subject that more men than women studied at her university. "You felt a little different; you did not fit like you would in the home economy. You were always competing and trying to survive because you belonged to a different group of people." The few female companions who she had directed their careers towards teaching. West also taught for a couple of years, but opportunities were opened elsewhere and that's how she went to work at the Dahlgreen naval base.

There, West collected and processed information from satellites, and used it to determine its exact position. It was this information that contributed to the development of GPS. "We came and sat at our desk and reasoned, we followed all the steps that anyone would follow to solve a mathematical problem," recalls West. Then she worked with the programmers on the functions that the computers needed to develop. "The operators called us to tell us that our program was going and that we could get closer to seeing it. Then we would go down and look at how that huge computer worked, and that's where we got results. Nine times out of ten were not quite right, so we had to analyze them to see what had turned out differently than we expected."

At the same time that West worked as a mathematician, the civil rights movement in the United States gained strength. Figures such as Martin Luther King and Malcom X denounced racism throughout the country. More than 250,000 people marched to the Lincoln Memorial in Washington to hear King's famous speech, "I have a dream." But West's work left her out of this movement. "It was something different because we were working for the government and we could not participate in questionable non-governmental activities," she says. "We lived at the base and we did not communicate very well with the community that we had nearby. We did not get involved in the civil rights movement, partly because it was not safe because of our work." Shortly after starting work at the base, West fell in love with the man who would become her husband. His name was Ira West. He was one of her two black colleagues. They got married and formed a family. They were together for more than 60 years. West continued working as a mathematician and her work was rewarded when the director of her department nominated her in 1979 to receive a mention. Thus, West was recommended to take over the project of the Seasat radio altimeter, the first satellite that could remotely observe the oceans.

After retiring in 1998 after a career of more than 40 years, West and her husband decided to celebrate this new stage in their lives traveling. Later, West returned to education and started a PhD that she had to interrupt when she suffered a stroke. This episode affected her hearing, sight, balance and mobility. "Suddenly," she says, "these words came to my mind: 'You can not stay in bed, you have to get up and finish your doctorate.'" And West did it. Later she suffered other health problems, including a breast cancer that was diagnosed a few years ago. Her story and achievements, however, did not come to light until a member of the brotherhood of her university, Alpha Kappa Alpha, read a short biography that West had delivered for an act of students. Since then, several articles about West appeared in the local press, students wrote about it and West was officially recognized by the Virginia Senate.

A joint resolution passed in February praised West "for her innovative career in mathematics and for her vital contribution to modern technology." In a message about Black History Month written in 2017, Captain Godfrey Weekes, then commander at Dahlgren, said that West had played a "fundamental role" in the development of GPS. "When Gladys West started her career as a mathematician at Dahlgren in 1956, she probably had no idea that her work would have an impact on the world for several decades." As for whether she was a role model for other women, West believes she put her grain of sand. "We have made a lot of progress since I arrived, because today, at least, you can talk about things and be a little more open. "Before, you had to whisper (...) Now the world is opening up a bit more and making it easier for women." However, she adds, "they still have to fight."